Why do they thrive? From David Brooks:
What matters are historical experiences, cultural attitudes, child-rearing practices, family formation patterns, expectations about the future, work ethics and the quality of social bonds.
Researchers have tried to disaggregate the influence of these soft factors and have found it nearly impossible. All we can say for sure is that different psychological, cultural and social factors combine in myriad ways to produce different viewpoints. As a result of these different viewpoints, the average behavior is different between different ethnic and geographic groups, leading to different life outcomes.